Kinesiology 01

Terms

the network of protein threads that gives structural support to the cell.

covalent bonds

very strong bonds that share electrons.

why is diffusion an effective method for the movement of molecules in fluid over short distances but not long distances

Diffusion is a passive method of transport and may not be effective in transporting molecules over long distances because it doesn't produce the energy or force required to move molecules long distances. (checking with tutor)

pH scale

The way that we express the concentration of hydrogen ions within solutions. 7 is neutral (water) pH less than 7 (0-7) are acids - HIGHER Hydrogen ion concentrations and they DONATE hydrogen ions, and pH of more than 7 are bases, with lower concentrations of hydrogen ions, i.e. THEY ACCEPT HYDROGEN IONS.

protein

more than a hundred peptides joined together (a BIG polypeptide = protein.)

peroxisomes

contain powerful oxidative enzymes that destroy toxic wastes produced in the cell, such as hydrogen peroxide and alcohol. Wastes are destroyed within the peroxisome , i.e neutralized while still in the cell.

the maintenance of the constancy of the internal environment of the body by the physiological body systems.

Transport proteins

Imbedded in the cell membrane, transport proteins transport molecules by changing shape or orientation in response to a molecule attaching them, then subsequently releasing the molecule on the opposite side, moving it from an area of high concentration to a lower concentration for that molecule.

theory

a scientific explanation to explain aspects of the world. hypotheses are used to support theories

secretory vessicles

small packages within the cell that contain products destined for export. secretory vessicles fuse with the cell membrane to secrete their products from the cell.

negative feedback

a stabilizing response of the body created and/or in response to overcome a change in the environment. For example, shivering to generate heat in response to sensing a colder atmosphere.

DNA

Deoxyribonucleic acid - the double-stranded molecules which store genetic material of the cell.

RNA

single stranded molecules of ribonucleic acid and the recipe for translation of DNA

gated channel proteins

integral proteins in the cell membrane, these open and close their 'gates' in response to chemical or electrical stimuli, allowing or disallowing passage through the cell membrane, of water and ions.

cell nucleus

a spherical membrane-bound organelle in the cell where genetic material (DNA) is stored.

carbohydrates

a backbone of carbon atoms, with hydrogen and oxygen attached in the same proportion as they normally appear in water

tissues

groups of cells with similar functions

protein structure - quaternary

number and type of protein chains in a structure.

ionic bonds

when oppositely charged ions are attracted to one another and join together to form neutral molecules. Not as strong as covalent bonds, so break apart easily, especially in aqueous solutions.

protein structure - secondary

degree of twisting into helix

three classes of organic molecules

carbohydrates (sugars and starches), lipids (fats and oils) and proteins.

protein structure - tertiary

overall shape of a single protein chain

nervous tissue

cells specialized for generating and transmitting electrical impulses, creating a communication network for the organism.

the primary storage form of lipids. One molecule of glycerol covalently bonded to three fatty acids. breakdown of triglycerides releases energy that can be used. (Synthesis requires energy.)

phospholipids

Have a glycerol molecule as the backbone, and two fatty acid tails. A negatively charged phosphate group and one other group that varies. This gives them one polar end and one non-charged end, with the polar end being water soluble and the non polar lipd end being insoluble in water. This is why a lipid bilayer is the building block of cell membranes.

polypeptide

chain of many amino acids.

ribosomes

attached to ER or floating freely in the cytoplasm, site of protein synthesis in the cell. Formed of two sub-units formed in and exported from the nucleus.

Why can glucose and amino acids not diffuse directly through the phospholipid bilayer in the same way as oxygen? --> checking with tutor.

Glucose and amino acids are not lipid soluble, therefore they are not able to easily cross the bilayer by diffusing through it in the same fashion as oxygen and carbon dioxide.

Four primary tissue types

muscle, connective, epithelial, nervous.

Smooth ER

rich supply of enzymes. synthesizes lipids, including steriod hormones. packages and delivers lipids and proteins to golgi complex by pinching off vessicles.

How can information be transmitted across the cell membrane even in the absence of molecular movement across the cell membrane?

Receptor proteins are integral proteins spanning the cell membrane, and are also enzymes. They can pass chemical messages through the cell membrane by causing an effect inside the cell in response to a stimuli outside of the cell.

Distinguish between smooth and rough ER & their products - how do materials get from ER to golgi?

a destabilizing physical response of the body that takes the natural environment of the body further away from normal in response to an environmental change. The physical responses enhance the effects within the body, of that environmental change

cytosol

the gell like material that fills the cavity of the cell.

hydrogen bonds

the weak attractive force between oppositely charged regions of molecules containing covalently bonded hydrogen atoms. (i.e. water holding together.) This is what allows water to flow - the hydrogen bonds are so weak that the bonds continually break and re-form.

hierarchy of a complex organism

atomic->molecular->cellular->tissue->organ->organ systems-> organism

golgi complex

contains enzymes that process products of ER into final form, adding sugards to proteins and lipids producing glycoproteins and glycolipids, which are packaged into vessicles for distribution in the cell.

microtubules & microfilaments

Small tube or elements of protein fibres of the cytoskeleton that serve to structurally support the cell and organelles.

receptor proteins

act to communicate with the environment of the cell transmitting chemical signals across the membrane, usually by triggering chemical events within the cell in response to a chemical stimuli from outside the cell.

ATP

Adenosine Tri-phosphate - the main energy source for the cell.

glycoproteins

have carbohydrate groups within them, allowing for attachment of the cytoskeleton within the cell, or for other cells to attach to the outer cell wall.

what would happen if an animal cell was placed in pure water?

diffusion of water is always towards a region with higher concentration of solutes, so the water would enter the cell, causing it to swell. If the cell didn't have a way of reducing the solute concentration, it would burst.

The double layer of phospholipid cells which makes up the cell membrane.

hydrolysis

the addition of a water molecule hydrates and breaks a bond between two monosaccharide molecules, breaking down the complex sugars into their component parts.

epithelial tissue

groups of cells which form sheets to cover or line organs (i.e. stomach lining, skin, kidney tubules.) Many epithelial cells are highly specialied for transporting materials across the cell layer, such as transfering nutrients from intestines into the bloodstream, and waste products from bloodstream into urine.

enzymes

proteins that facilitate chemical reactions in living cells, causing the reactions to become substantially more efficient.

Protein pumps

embedded in the cell membrane, these are efficient proteins involved in active transport of molecules across a membrane, in both directions, and at times with multiple molecules. The Na+-K+ pump is an example.

dehydration synthesis

connecting simple sugars by removing the equivalent of one water molecule. (Two hydrogen and one oxygen.)

protein - quaternary structure

the number and type of chains of a protein.

diffusion

net movement of particles from one region to another as a result of random thermal motion, from a region of high concentration to a region of lower concentration. Requires this concentration difference.

peptide

when, through dehydration synthesis, two or more amino acids are linked.

membrane channels

Water channels, and chemically or electrically gated channels that pass through the cell membrane allowing or disallowing the passage of water and ions. "pipes" through the cell membrane, some open, some closed, some with "valves.